Enhanced near-infrared reflectance and functional characteristics of nano metal oxide embedded alkyd coatings

Abstract

The main idea of the research is to formulate alkyd based smart coatings with high NIR-reflectance to decrease the cooling load in order to maintain cool comfort in buildings. In addition to the NIR reflectance studies, the physical characteristics of the coating such as glossiness, hiding power, spreading area, volatile organic contents are evaluated. Heat reflective coatings are prepared by ball milling technique utilizing white metal oxide nanoparticles (NPs) titanium oxide (TiO2), zinc oxide (ZnO) and zirconium oxide (ZrO2) as pigments. The x-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) results reveal the prepared metal oxide pigments are of high purity. Bonding interaction between the alkyd resin and the NPs are studied using Fourier transform infrared spectroscopy (FTIR).The spectral reflectance of the prepared coatings are measured using spectrophotometer in the solar spectrum range, wherein ZnO based nanocoatings shows better results. The cool comfort is measured for ZnO nanocoatings in an enclosed glass cabinet and the differences in temperature with respect to exposure to sunlight are highlighted. Finally, a prototype coated with ZnO NPs maintains lower indoor temperature than the commercially available white paint coated model in the order of 2.7 °C.